Sending mail multiple times by Microsoft Graph - asp.net-core

Question

Blazor server application
I have a web appliction that is using AzureAd and OpenIdConnect to login to this application.
I am sending mail by using Microsoft graph and I am using the example in Microsoft doc with some changes like this:
#inject Microsoft.Graph.GraphServiceClient GraphServiceClient
#inject MicrosoftIdentityConsentAndConditionalAccessHandler ConsentHandler
var message = new Message
{
Subject = "Meet for lunch?",
Body = new ItemBody
{
ContentType = BodyType.Text,
Content = "The new cafeteria is open."
},
ToRecipients = new List<Recipient>()
{
new Recipient
{
EmailAddress = new EmailAddress
{
Address = "fannyd#contoso.onmicrosoft.com"
}
}
},
CcRecipients = new List<Recipient>()
{
new Recipient
{
EmailAddress = new EmailAddress
{
Address = "danas#contoso.onmicrosoft.com"
}
}
}
};
var saveToSentItems = false;
try
{
await GraphServiceClient.Me
.SendMail(message,saveToSentItems)
.Request()
.PostAsync();
}
catch(Exception ex)
{
ConsentHandler.HandleException(ex);
}
Scenario of the error
This works perfect but just for one time , if I try to send the same email again it doesn't work and I got no error but just redirect me to empty page.
If I logout and login again, then it works fine.
The error that I got in the second time:
Message = "IDW10502: An MsalUiRequiredException was thrown due to a challenge for the user. See https://aka.ms/ms-id-web/ca_incremental-consent. "
MsalUiRequiredException = {"No account or login hint was passed to the AcquireTokenSilent call. "}
My Question
How can fix the code up to send multi emails?. I think that I have a problem with token but I don't know where should I start?.
Thanks

Answer 1

Add the other catch block to retrieve the specific issue if we have any related to permissions or other ServiceExceptions.
try
{
SendMail(); // Sending mail code here.
}
catch (Microsoft.Graph.ServiceException e)
{
// get the error here if we have any.
}

Answer 2

After some search, I think that I have to move the the permission Delegated permissions to Application Permissions like this:
Why should I use application permission?
In my case the user logged in for the first time and clicked on the button then the email will be send, but in the second time the application has to communicate with API graph without interaction from the user, that means without user and this exactly what I need(application permission).
I adjust the code like the following:
Client credentials provider:
The client credential flow enables service applications to run without user interaction. Access is based on the identity of the application. this is from Microsoft doc
private GraphServiceClient CreateGraphServiceClient()
{
// The client credentials flow requires that you request the
// /.default scope, and preconfigure your permissions on the
// app registration in Azure. An administrator must grant consent
// to those permissions beforehand.
var scopes = new[] { "https://graph.microsoft.com/.default" };
// Multi-tenant apps can use "common",
// single-tenant apps must use the tenant ID from the Azure portal
var tenantId = "common";
// Values from app registration
var clientId = "YOUR_CLIENT_ID";
var clientSecret = "YOUR_CLIENT_SECRET";
// using Azure.Identity;
var options = new TokenCredentialOptions
{
AuthorityHost = AzureAuthorityHosts.AzurePublicCloud
};
var clientSecretCredential = new ClientSecretCredential(
tenantId, clientId, clientSecret, options);
return new GraphServiceClient(clientSecretCredential, scopes);
}
Send mail with UserId, you can see the code in Microsoft doc:
puplic SendMyEmail()
{
GraphServiceClient graphClient = CreateGraphServiceClient;
var message = new Message
{
Subject = "Meet for lunch?",
Body = new ItemBody
{
ContentType = BodyType.Text,
Content = "The new cafeteria is open."
},
ToRecipients = new List<Recipient>()
{
new Recipient
{
EmailAddress = new EmailAddress
{
Address = "fannyd#contoso.onmicrosoft.com"
}
}
},
CcRecipients = new List<Recipient>()
{
new Recipient
{
EmailAddress = new EmailAddress
{
Address = "danas#contoso.onmicrosoft.com"
}
}
}
};
var saveToSentItems = false;
//See GetUserId down
string userId = await GetUserId();
await graphClient.Users[UserId]
.SendMail(message,saveToSentItems)
.Request()
.PostAsync();
}
}
UserId:
To get user Id you need AuthenticationStateProvider, this has to inject in the service of your application and then add to the constructor of your class, then you can use it.
puplic class MyClass
{
private readonly MicrosoftIdentityConsentAndConditionalAccessHandler ConsentHandler;
private readonly AuthenticationStateProvider authenticationState;
puplic MyClass(
MicrosoftIdentityConsentAndConditionalAccessHandler ConsentHandler,
AuthenticationStateProvider authenticationState)
{
this.authenticationState = authenticationState;
this.ConsentHandler = ConsentHandler;
}
public async Task<string> GetUserId()
{
var authSate = await authenticationState.GetAuthenticationStateAsync();
return authSate.User.FindFirstValue("http://schemas.microsoft.com/identity/claims/objectidentifier");
}
//Here your
private GraphServiceClient CreateGraphServiceClient() { ...}
puplic SendMyEmail() {....}
}